﻿using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Diagnostics.CodeAnalysis;
using System.Globalization;
using System.Text;
using Pfz.DataTypes;
using Pfz.Extensions;

namespace Pfz.WpfControls
{
	/// <summary>
	/// This class allows to convert strings to full observable-collections of
	/// PropertyBounds.
	/// Examples:
	/// FullTypeName.* (which will get all properties from that interface type and parent interfaces).
	/// FullTypeName:* (which will get all properties from that interface type, without parent interfaces)
	/// FullTypeName:PropertyName;OtherPropertyName
	/// FullTypeName:PropertyName=Display name;OtherPropertyName=Other display name
	/// FullTypeName.PropertyName=Display name;OtherFullTypeName.PropertyName=Other display name
	/// FullTypeName:*|OtherInterfaceType.PropertyName
	/// </summary>
	public class PropertyBindingsConverter:
		TypeConverter
	{
		/// <summary>
		/// Returns true for strings.
		/// </summary>
		public override bool CanConvertFrom(ITypeDescriptorContext context, Type sourceType)
		{
			return sourceType == typeof(string);
		}

		/// <summary>
		/// Returns true for strings.
		/// </summary>
		public override bool CanConvertTo(ITypeDescriptorContext context, Type destinationType)
		{
			return destinationType == typeof(string);
		}
		
		/// <summary>
		/// Creates a PropertyBinding from a string.
		/// </summary>
		[SuppressMessage("Microsoft.Performance", "CA1820:TestForEmptyStringsUsingStringLength")]
		public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object value)
		{
			string strValue = value as string;
			if (string.IsNullOrEmpty(strValue))
				return null;
				
			string[] pipedStrings = strValue.Split('|');
			
			List<PropertyBinding> list = new List<PropertyBinding>();
			foreach(var pipedString in pipedStrings)
			{
				if (pipedString.EndsWith(".*"))
				{
					string typeName = pipedString.Substring(0, pipedString.Length-2);
					Type type = TypeTypeConverter.ConvertFrom(typeName);
					foreach(var propertyInfo in type.GetInterfaceProperties())
					{
						PropertyBinding propertyBinding = new PropertyBinding();
						propertyBinding.Property = propertyInfo;
						list.Add(propertyBinding);
					}

					continue;
				}
			
				string prefix = null;
				strValue = pipedString;
				int pos = strValue.IndexOf(':');
				if (pos != -1)
				{
					prefix = strValue.Substring(0, pos) + '.';
					strValue = strValue.Substring(pos+1);
				}
				
				string[] propertyBoundStrings = strValue.Split(';');
				int count2 = propertyBoundStrings.Length;
				for(int i=0; i<count2; i++)
				{
					string propertyBoundString = propertyBoundStrings[i];
					
					if (propertyBoundString == "")
					{
						list.Add(null);
						continue;
					}
					
					if (prefix != null && propertyBoundString.IndexOf('.') == -1)
					{
						if (propertyBoundString == ("*"))
						{
							string typeName = prefix.Substring(0, prefix.Length-1);
							Type type = TypeTypeConverter.ConvertFrom(typeName);
							
							// here is getproperties, not getinterfaceproperties.
							foreach(var propertyInfo in type.GetProperties())
							{
								PropertyBinding propertyBinding = new PropertyBinding();
								propertyBinding.Property = propertyInfo;
								list.Add(propertyBinding);
							}

							continue;
						}

						propertyBoundString = prefix + propertyBoundString;
					}
						
					
					PropertyBinding propertyBound = PropertyBindingConverter.ConvertFrom(propertyBoundString);
					list.Add(propertyBound);
				}
			}
			return new ObservableCollection<PropertyBinding>(list);
		}
		
		/// <summary>
		/// Gets the string representation of a property binding.
		/// </summary>
		public override object ConvertTo(ITypeDescriptorContext context, CultureInfo culture, object value, Type destinationType)
		{
			var collection = value as ObservableCollection<PropertyBinding>;
			if (collection == null)
				return null;
			
			if (collection.Count == 0)
				return "";
				
			StringBuilder result = new StringBuilder();
			foreach(var propertyBound in collection)
			{
				string propertyBoundString = PropertyBindingConverter.ConvertTo(propertyBound);
				result.Append(propertyBoundString);
				result.Append(';');
			}
			result.Length--;
			
			return result.ToString();
		}
	}
}
